The Rock CycleThe Rock Cycle

By:Brianna Shields

January 25, 2005

DO NOWDO NOW

• 1. Which mineral characteristic is tested by rubbing the mineral on a porcelain tile or plate?

• 2. Which mineral characteristic is tested by scratching the mineral across other minerals or across items such as a nail, penny or glass?

• 3. How do you determine a mineral’s cleavage?

GOALGOAL

• To know the three rock types, their formation, and the paths they might travel through during the rock cycle

Video: Rock CycleVideo: Rock Cycle

• Focus Questions: How are igneous rocks formed? How are metamorphic rocks formed? How are sedimentary rocks formed?

Video: Rock CycleVideo: Rock Cycle

QuickTime™ and aSorenson Video 3 decompressorare needed to see this picture.

Rock CycleRock Cycle

• Rock Cycle

• Continuous changing of rocks from one kind to another Takes long periods of time

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• Igneous Rocks

• 1. Formed when magma or lava hardens

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• Igneous Rocks

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• Igneous Rocks

• 2. Classified by texture and what they are made of

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• Igneous Rocks

• 3. Type depends on how fast or slow the lava cools Slow cool = large crystals Rapid cool= small crystals

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• Igneous Rocks

• 4. Samples Obsidian- cooled extremely

fast• Microscopic Crystals

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• Igneous Rocks

• 4. Samples Basalt- cooled quickly• Small Crystals

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• Igneous Rocks

• 4. Samples Granite- cooled slowly• Large Crystals

Igneous RocksIgneous Rocks

• See if you can pick samples of obsidian, granite and basalt out of your mineral kit Do not use the key to help you! Use your memory of the powerpoint

pictures!

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• Sedimentary Rocks

• 1. Formed when layers of sediment harden Rock bits harden into new rocks

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• Sedimentary Rocks

• 2. Two ways to harden: Pressure from sediment weight Cementing by other minerals

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• Sedimentary Rocks

• 3. Form where rivers meet oceans, as sediments are dumped

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• Sedimentary Rocks

• 4. Samples A. Shale- made from mud and

clay

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• Sedimentary Rocks

• 4. Samples B. Sandstone- made from sand

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• Sedimentary Rocks

• 4. Samples C. Conglomerate- made from

sand, pebbles and rocks

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• Sedimentary Rocks

• 4. Samples D. Limestone- made from shells

of dead sea animals

Sedimentary RocksSedimentary Rocks

• See if you can pick samples of shale, sandstone, conglomerate, limestone out of your mineral kit Do not use the key to help you! Use your memory of the powerpoint

pictures!

Rock CycleRock Cycle

• Metamorphic Rocks

• 1. Rocks changed into new rocks due to high heat and great pressure

Rock CycleRock Cycle

• Metamorphic Rocks

• 2. Form deep in Earth

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• Metamorphic Rocks

• 3. Samples Quartzite- forms from sandstone

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• Metamorphic Rocks

• 3. Samples Marble- forms from limestone

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• Metamorphic Rocks

• 3. Samples Slate- forms from shale

Metamorphic RocksMetamorphic Rocks

• See if you can pick samples of quartzite, marble and slate out of your mineral kit Do not use the key to help you! Use your memory of the powerpoint

pictures!

The Rock CycleThe Rock Cycle

• Use what you have learned to create a rock cycle diagram. Include: Where and how each type of rock is found Mountain River Ocean Volcano 2 upper layers of the earth’s interior

Rock Cycle DiagramsRock Cycle Diagrams

Rock Cycle DiagramsRock Cycle Diagrams

Rock Cycle DiagramsRock Cycle Diagrams

Identifying RocksIdentifying Rocks

• Pull rocks numbers 3, 4 out of the rock kit.

• Observe each rock

• Determine whether the rock is most likely igneous, sedimentary or metamorphic

• Support your answer with evidence

Interactive WebsitesInteractive Websites

• Interactive Rock Cycle Animation

Assessment: Rock CycleAssessment: Rock Cycle

• When rock fragments are compacted and cemented, what type of rocks do they become?

Assessment: Rock CycleAssessment: Rock Cycle

• When metamorphic rocks are melted what do they become?

Assessment: Rock CycleAssessment: Rock Cycle

• When magma cools and hardens, what type of rocks are formed?

Assessment: Rock CycleAssessment: Rock Cycle

• When sedimentary rocks are really heated up and pressure is applied, what do they become?

Assessment: Rock CycleAssessment: Rock Cycle

• When igneous rocks are weathered and eroded, what do they become?

Assessment: Rock CycleAssessment: Rock Cycle

• What is the softest mineral on Moh’s hardness scale?

Assessment: Rock CycleAssessment: Rock Cycle

• The breaking of a mineral along smooth, definite surfaces is called?

Assessment: Rock CycleAssessment: Rock Cycle

• The way in which a mineral reflect light from its surface is its?

Assessment: Rock CycleAssessment: Rock Cycle

• What are atleast 5 mineral properties/tests used to identify minerals?

Assessment: Rock CycleAssessment: Rock Cycle

• Relate the cooling rate of magma to the crystal size in igneous rocks

Assessment: Rock CycleAssessment: Rock Cycle

• The gemstone opal is a sedimentary rock that consists of microscopic balls of silica cemented together by water. Explain how an opalized clam shell may have formed.

Assessment: Rock CycleAssessment: Rock Cycle

• Obsidian and diorite are both igneous rocks. Obsidian looks like black glass. At a distance, diorite is dark gray; up close, it becomes clear that it is made of black, gray and white grains. How do you account for the differences in these two rocks?

Assessment: Rock CycleAssessment: Rock Cycle

• Suppose you have found a large mass of igneous rock between layers of sedimentary rock. Between the bottom of the igneous rock and the sedimentary rock you observe a thin layer of quartzite. The igneous rock itself is fine grained and very dark. What can you infer about the igneous formation’s history?